The NRL said it would take whatever action is necessary to protect the players and staff of the Newcastle Knights after their wages were not paid on Thursday.
The NRL learned on Friday that the Newcastle Knights, controlled by Nathan Tinkler's Hunter Sports Group, had failed to pay the salaries of at least 20 staff and players.
"The NRL will take whatever action is necessary to protect the Knights, the game and, most importantly, the players and staff as a result of these actions," NRL CEO, Dave Smith, said.
NRL head of club services, Tony Crawford, said: "The actions of the Tinkler-controlled Knights towards players and staff are completely unacceptable and will not be tolerated.
"The NRL has demanded that the situation is rectified immediately because there is no place in our game for this kind of behaviour.
"The NRL will be assessing all options to bring this to a resolution in the interests of the Knights, staff, our fans and the broader Rugby League community."
The NRL said it would not speculate on what those options might include.
News of the Knights' plight comes as the team prepares to take on arch rivals Manly at Brookvale Oval on Monday.
Former NSW and Australian halfback Greg Alexander urged Knights captain Kurt Gidley and fullback Darius Boyd to reignite the NRL's least potent attacking team.
Newcastle (23) have scored fewer tries than any other team this season.
The premiership-winning former Penrith skipper said Boyd owed it to Knights fans to "pull his finger out" before heading into camp next week with Queensland's record-breaking State of Origin team.
Alexander said: "Darius Boyd has started the year in terrible fashion ... the marquee man has to fire and he's got quality players to work with on the outside.
"If he comes out and plays well at Origin level, you'd have to start thinking as a teammate or a fan, 'Well, what's he doing for us?"'